1. Field of the Invention
The present invention relates to a printing apparatus and its control method having a plurality of emulation programs to output data using an emulation program adapted to the input data.
2. Related Background Art
Conventionally, in the printing apparatus having a plurality of emulation programs, the following methods for switching the emulation program have been provided.
1. An emulation identification command is input prior to the print data, and the emulation program is switched in accordance with it.
2. A predetermined amount of data among the print data received is compared with the command code of each emulation program, its use frequency is calculated, and the emulation program is switched in accordance with the calculated value.
However, in the first method of the conventional example as above mentioned, it is necessary to know in advance the emulation program to be used, while in the second method, it takes a lot of time to discriminate the emulation program.
Also, in the second method, the command which each emulation program interprets contained in the received data is analyzed, but if a command analysis table where the commands usable for the analysis are registered is contained within the control program of controlling the printing apparatus, an automatic emulation switching function is only operable under the support of predetermined emulation programs, whereby there was a drawback that a newly supported emulation program could not be operated.
Also, there may be a plurality of commands having the same meaning, depending on the emulation, whereby there was a drawback that it took a lot of time in discriminating the emulation program to separately register or retrieve such commands in or from the command table.